Status Report

Hubble Space Telescope Daily Report #3023 – 21 Dec 2001

By SpaceRef Editor

December 21, 2001

Filed under Hubble Space Telescope, Space Telescope Science Institute, US

HUBBLE SPACE TELESCOPE

DAILY REPORT #3023

PERIOD COVERED: 0000Z (UTC) 12/20/01 – 0000Z (UTC) 12/21/01

Daily Status Report as of 355/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed FGS/1 9183 (Completing the Astrometric Orbit for a Pair
of Pre-Main Sequence Low-Mass Stars)

Fine Guidance Sensor #1 was used to resolve a visual binary that is
part of the closest system of pre-main sequence stars, HD 98800. This
system is 50 pc away and this binary has a period just under a year,
meaning the separation is about 20 milliarcsec. The two stars have similar
brightnesses. The goal is to determine an astrometric orbit which, when
combined with radial velocity observations, leads to the first
dynamically-determined masses for low-mass pre-main sequence stars. All
observations completed normally.

1.2 Completed Eleven Sets of WF/PC-2 9244 (POMS Test Proposal: WFII
Parallel Archive Proposal Continuation)

The WF/PC-2 was used to perform a generic target version of the
Archival Pure Parallel program. The program will be used to take parallel
images of random areas of the sky, following the recommendations of the
Parallels Working Group. The observations completed with no anomalous
activity.

1.3 Completed Five Sets of STIS/CCD 9285 (POMS Test Proposal: STIS
Non-scripted Parallel Proposal Continuation III)

The Space Telescope Imaging Spectrograph (CCD) was used to make low
galactic latitude, non-scripted parallel observations as part of a POMS
test proposal. The observations were completed as planned, and no
anomalies were reported.

1.4 Completed Five Sets of WF/PC-2 8937 (Cycle 9 Supplemental Darks pt2/3)

The WF/PC-2 was used obtain three dark frames every day to provide
data for monitoring and characterizing the evolution of hot pixels. No
problems were encountered.

1.5 Completed STIS/CCD 9070 (A Census of Nuclear Star Clusters in
Late-Type Spiral Galaxies: II. Spectroscopy and Stellar Populations)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate spiral galaxies that have a prominent star cluster in their
dynamical center. Statistics for cluster frequency, size, and luminosity
remain incomplete. The proposal completed as planned.

1.6 Completed STIS/CCD 9177 (Tidal Disruption of Stars by Massive Black
Holes in Galaxy Nuclei: After the Flare)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
supermassive black hole that will rip apart a star that strays within its
tidal radius, causing an Eddington-limited UV/X-ray flare for several
months as the orbiting debris accretes. While such events are predicted to
occur at most once in 10^4 yr per galaxy, an experiment was performed in
1990-91 which sampled hundreds of thousands of galaxies in the ideal
wavelength band. Three galaxies had unusual X-ray flares, but no evidence
for nuclear activity in ground-based spectra. To establish beyond a
reasonable doubt that these were tidal disruption events, it is proposed to
make a sensitive search for permanent Seyfert activity, the only possible
alternative to the disruption hypothesis. Nuclear optical spectra obtained
through a narrow slit will reject most of the starlight and place limits on
AGN-like emission line activity below those of the weakest
Seyferts. Masses of black holes could be studied by monitoring the
outburst light curves and the spectra of the tidal debris. The proposal
completed with no reported problems.

1.7 Completed STIS/CCD 9088 (Next Generation Spectral Library of Stars)

The Space Telescope Imaging Spectrograph (CCD) was used to produce
a “Next Generation” Spectral Library of 600 stars for use in modeling the
integrated light of galaxies and clusters by using the low dispersion UV
and optical gratings of STIS. The library will be roughly equally divided
among four metallicities, very low {Fe/H < -1.5}, low {-1.5 < Fe/H < -0.5}, near-solar {-0.5 < Fe/H < 0.1}, and super-solar {Fe/H > 0.1}, well-sampling
the entire HR-diagram in each bin. Such a library will surpass all extant
compilations and have lasting archival value, well into the Next Generation
Space Telescope era. No problems occurred.

1.8 Completed WF/PC-2 9124 (Mid-UV SNAPSHOT Survey of Nearby
Irregulars: Galaxy Structure and Evolution Benchmark)

The WF/PC-2 was used to investigate the relation between star
formation and the global physical characteristics of galaxies to interpret
the morphologies of distant galaxies in terms of their evolutionary
status. Distant galaxies are primarily observed in their rest frame
mid-ultraviolet. They resemble nearby late-type galaxies, but are they
really physically similar classes of objects? It is proposed to address
this question through a SNAPSHOT survey in the 2 mid-UV filter F300W of 98
nearby late-type, irregular and peculiar galaxies. No problems were reported.

1.9 Completed STIS/CCD 9143 (Spectrophotometry of Nearby Seyfert 2
Nuclei: Can We Eliminate the Seyfert 2 Class?)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate Seyfert 2s that are distinguished by the absence of the broad
emission lines characteristic of Seyfert 1s and more luminous QSOs. Are
Seyfert 2s fundamentally different from Seyfert 1s and their brighter
cousins? Or is the broad emission line region in Seyfert 2s simply
suppressed by obscuring material as postulated by the unification
model? If the latter model is correct, the weak broad emission lines in
the Seyfert 2s may simply be overwhelmed by starlight from the
circumnuclear region, particularly in the case of recent star
formation. It is proposed to determine if all Seyfert 2s have {weak} broad
emission line regions by obtaining long-slit STIS spectroscopy for a
well-defined sample of 20 Seyfert 2s {3 archival, 17 new}. The
observations completed with no anomalous activity.

1.10 Completed STIS/CCD 8903 (Bias Monitor – Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at
gain = 4 to build up high-S/N superbiases and track the evolution of hot
columns. There were no problems.

1.11 Completed FGS/1 8897 (Long Term Monitoring of FGS1R in Position Mode)

Fine Guidance Sensor #1R was used to monitor its long-term
evolution, presumably due to disorption of water from the instrument’s
graphite epoxy composits. This manifests principally as a change in the
plate scale and secondarily as a change in the distortions. These effects
are well modeled by adjustments to the rhoA and kA parameters which are
used to transform the star selector servo angles into FGS {x, y} detector
space coordinates. By observing the relative positions of stars in a
standard cluster at a fixed telescope pointing and orientation, the
evolution of rhoA and kA can be monitored and calibrated to preserve the
astrometric integrity of the FGS. There were no reported problems.

1.12 Completed Two Sets of STIS/CCD 8901 (Dark Monitor-Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks. There was no anomalous activity.

1.13 Completed Two Sets of FGS/1 8898 (Calibrating FGS1r’s
Interferometric Response as a Function of Spectral Color)

Fine Guidance Sensor #1 was used to obtain reference point source
Transfer Functions {S-Curves} through the F583W filter and the F5ND
attenuator at the center position of the FGS1r FOV for a variety of stellar
spectral colors. The data will be added to the library of point source
interferograms that was assembled from the Cycles 8 and 9 calibration
program. These Transfer Functions are needed to support the analysis of GO
science data for the study of close and wide binary star systems and for
determining the angular diameter of extended sources. The proposal
completed with no reported problems.

1.14 Completed STIS/CCD/MA2 9166 (Fossil Gaseous Halos of Massive
Galaxies at z~1)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe host galaxies of high-redshift, powerful radio sources that are
likely the progenitors of present-day gE and cD galaxies, and therefore
provide important laboratories in which to investigate the formation of
massive galaxies in the early Universe. Many high-redshift radio galaxies
exhibit giant, Ly-alpha halos. Similar nebulae without associated radio
sources have recently been discovered in a galaxy overdensity at z =
3.09. The LyAlpha luminosity of these halos is comparable to the total
X-ray luminosities of low–z X–ray clusters, and may reflect the hot,
cooling gas reservoir from which the galaxy/cluster is forming. The
observations completed as planned.

1.15 Completed Three Sets of WF/PC-2 8941 (Cycle 10 UV Earthflats)

The WF/PC-2 was used to monitor flat field stability by obtaining
sequences of earth streak flats to improve the quality of pipeline flat
fields for the WFPC2 UV filter set. The proposal had no problems.

1.16 Completed WF/PC-2 8942 (Cycle 10 Intflat Sweeps and Linearity Test)

The WF/PC-2 was used to monitor the pixel-to-pixel flatfield
response and provide a linearity check. These intflat sequences are done
once during the year and the images will provide a backup database in the
event of complete failure of the visflat lamp as well as allow monitoring
of the gain ratios. There were no reported problems.

1.17 Completed STIS/CCD/MA1 9036 (An Ultraviolet Spectroscopic Survey
of Star-Forming Galaxies in the Local Universe)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
perform a comprehensive STIS ultraviolet spectroscopic survey of
star-forming galaxies in the local universe. The sample covers a broad
range of morphologies, chemical composition, and luminosity. The
observations will provide spectral coverage between 1200 and 3100 Angstrom,
at a resolution of 100 to 200 kms and S/N of about 30. The data set will
allow the proposers to document and quantify the effects of massive stars
on the interstellar medium and to infer implications for the evolution of
the host galaxies. The proposal completed with no anomalous activity.

1.18 Completed STIS/CCD 9148 (Light Echos and the Nature of Type Ia
Supernovae)

The Space Telescope Imaging Spectrograph (CCD) was used to take
STIS snapshot images of a subset of 43 well observed Type Ia supernovae
{SNIa}, most of which have been discovered in late type galaxies over the
last 40 years to make a systematic search for light echos around SN
Ia. STIS will also observe a sample of 10 SN II and SN Ib/c, which are
believed to be the result of massive star core collapse and, therefore, to
be thin-disk population objects, in order to make an empirical calibration
of the accuracy of our method for determining scale heights. The SN Ia
sample will provide a direct as well as accurate estimate of the scale
height of SN Ia which is an important clue to the progenitors of these
events. The proposal completed nominally.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 8

Successful: 8

Scheduled Re-acquisitions: 7

Successful: 7

2.2 FHST Updates:

Scheduled: 21

Successful: 21

2.3 Operations Notes:

The operations team participated in Joint Integrated Simulation #7
(Two Short Deploys) from 9:00 a.m. until 6:00 p.m.

Using ROP SR-1A, the SSR-1 EDAC error counter was cleared at 354/1842Z.